Astronomers like to find rotating primordial discs of gas and dust around young stars from which planets can form. They might be able to catch the star partway through the planet-formation process, but it’s highly unusual to find such discs around brown dwarfs or stars with very low masses. Now, recent work reveals four new low-mass objects surrounded by discs.
Brown dwarfs are sometimes called failed stars as they are too small to sustain the hydrogen fusion process that powers stars. Their temperatures can range from nearly as hot as a star to as cool as a planet and their masses also range between star-like and giant-planet-like. A near-infrared survey has discovered several ultracool brown dwarfs in the Sun’s vicinity.
A group of researchers using the W. M. Keck Observatory have discovered a planet-like body that may have been encrusted in limestone and is having its surface layers devoured by its deceased host star. The team found that the rocky material being accreted by the star could be comprised of minerals that are typically associated with marine life processes here on Earth.